1. Field of the Invention
The present invention relates to a method and apparatus for processing multiple files, and more specifically, to assembling a set of input files into one output file.
2. Description of Related Art
Printing refers to the reproduction of words and pictures on a page or document. Today, the high volume production machines of the major printing processes are the presses, which use plates (or other types of image carriers) to transfer the ink onto the paper or substrate. These processes are often used to support markets such as commercial printing, magazines, newspapers, catalogs, books, business forms, greeting cards, maps, labels, packaging, and other printed products.
One common type of production printing process is the offset printing process which uses an intermediate blanket cylinder to transfer an image from the image carrier to the substrate. In general, printing operations include, prepress operations, press operations, and postpress operations. The offset printing process, and in particular its prepress operations, involve intricate manual operations which are very time consuming and cost intensive, and require highly skilled expensive professionals.
FIG. 1 illustrates a flowchart for an offset printing process. The first four steps 100, 110, 120, and 130 represent the prepress operations 140 of an offset printing process. The first step 100 involves the layout and preparation of the materials to be used in the production printing. For example, checking for the desired size and other details for illustration, and the arrangement into the proper position of various parts of the page to be photographed. At this stage, the raw pages may provide input into a camera or other imaging device.
Next in step 110, the imaging operation is performed. During the imaging operation images for reproduction are collected, created and/or corrected prior to assembly for platemaking. Photography may be used to make the images for the plates. When using photography, the individual films must be properly prepared before they can be assembled to make the plates. Digital cameras and digital scanners and software may also be used to produce digital files for making the plates.
Then in step 120, the imaging assembly operation assembles all of the image elements to create pages and signature forms for printing. Note that generally books and other publications are printed in units of a number of pages per sheet called signatures. There may be from two to sixty-four pages on each side of the sheet, depending on the size of the page, the signature, the form to be printed, and the press. Thus, if there are 1600 pages for a particular book to be printed and there are 16 pages per signature, then 100 offset plates (i.e., each offset plate produces a particular signature) are required to print the entire book. The offset plates provide the input to the offset printing press. The assembly process ensures that when the sheet is printed, folded and trimmed, the pages will appear in the proper sequence.
The last step 130 in the prepress operations represents the actual platemaking (or image carrier) process. Today, many platemaking processes are available.
Once all the prepress operations are completed, the offset printing press is used to print multiple copies of several different sheets. As stated above, each offset plate is used to produce one signature, which represents a collection of individual pages after it has been folded, slit, trimmed, etc. When using an offset printing press, each offset plate must be input into the press. Once an offset plate is inserted into the press, multiple copies of one particular sheet are printed. Each sheet represents a printed copy of multiple pages and may be single-sided (simplex) or double-sided (duplex). Note that each sheet is eventually folded, slit, trimmed, etc. to create a copy of the individual pages within the signature. The offset printing process repeats this process (i.e., inserting an offset plate and printing multiple copies of a sheet) until all offset plates have been used as input into the offset press. Thus, a book or publication is typically made up of many individual signatures, which are like sections in a book, which are combined in the desired order to form a book. Where appropriate for the proper sequence of pages, blank pages are manually or programmatically added to the book or publication.
Once all the sheets have been printed, the printed sheets are combined into a single document having multiple pages (i.e., books, catalogs, magazines, pamphlets, or other publications). The postpress operations shown in box 160 include operations such as binding, finishing and distribution.
Although the offset press printing process, and other printing processes that use plates are cost effective when printing high volumes of documents, it is often not practical for printing smaller volumes. For printing press systems, the unit cost of prints decrease as the quantities increase. Thus, printing press systems typically require several thousands of copies of a document to be printed in order to be profitable.
With the development of digital image processing, digital printing systems may be used to improve the productivity, quality, and efficiency of many printing operations. Many digital printing systems use a plateless printing process. Common plateless digital printing processes include electrophotography, ink-jet, and thermal transfer, etc. Digital printing systems are often desirable over printing press processes because (1) most of the equipment are suitable for an office environment (2) its capabilities of variable printing from impression-to-impression; and (3) requires less manual skills than printing on conventional plate presses.
Under certain circumstances, it is particularly advantageous to use a digital printing system to produce documents. For example, it is more cost effective to print a small volume of documents (e.g., books, catalogs, magazines, etc.) with a digital printing system rather than an offset printing press, particularly when printing on-demand or when the document contains a large number of loose leaf pages.
One conventional digital printing system reproduces a multiple-page document by printing multiple jobs. Each print job includes one or more electronically stored print files. Each print file may be used to reproduce a single loose leaf page (also referred to as a xe2x80x9cfolioxe2x80x9d page) in a multiple page document such as a book. Or alternatively, the various print files in a particular document may be combined manually using a xe2x80x9cjob ticketxe2x80x9d or similar construct to create a single print job to reproduce a multiple-page document. Typically, a job ticket is used to define the print attributes for a print job. A print job is generally assembled and created by a data processing system (e.g., a client computer or a workstation) and submitted to a digital printing system, or alternatively assembled and created by a highly sophisticated printing system.
When these types of digital printing processes are used to reproduce documents, blank pages must be added. Furthermore, the print time for multiple print jobs is typically longer than the print time for a single print job for reproducing a multiple-page document, particularly a voluminous document. Additionally, as the document gets larger (i.e., increase in number of pages) the likelihood that the pages may get out of order increases. Furthermore, when multiple print files are used to reproduce a multiple page document, it is more cumbersome to store, back-up, recover, or print the multiple print files as compared to a single print file.
As the printing industry transitions from conventional printing press operations to digital printing operations to take advantage of the technological advances made in digital imaging, it is possible to provide a more automated printing process. One approach to providing a more automated digital printing process is to store, back-up, recover, and print a multiple-page document as a single object.
It is an object of the present invention to assemble a collection of individual files into a single file.
A method and apparatus of assembling a set of page files into a document file is described. A set of page files, which represents one page or a group of pages within a document, is received as input files. For one embodiment of the present invention, the page files and document files are written in a page description language. The correct sequence of the pages within the document is determined. Then, a framework for a document file is created. The framework is created to include all or a portion of the pages from the set of page files. One or more of the pages within the page files are modified to fit into the framework and then stored within the document framework. The document file is then stored.
One aspect of the present invention includes creating one or more blank pages within the document framework.
An additional aspect includes removing document constructs in one or more of the page files that do not define the page file as being a page within the document framework.
Another aspect includes adding document constructs in one or more of the page files that are necessary to define the page file as being a page within the document framework.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description below.